1. Field of the Invention
The present invention relates generally to a plate type, non-welded heat exchanger configuration and more particularly to a plate type, non-welded heat exchanger configuration which facilitates fluid flow through the heat exchanger along a generally "L" shaped path from one face to a face disposed at right angles thereto or facilitates the entry or exit of both fluids on the same face or on opposing parallel faces. The invention also relates to a heat exchanger plate configuration for use in the above heat exchanger.
2. Description of the Prior Art
Various types of heat exchangers currently exist for transferring heat from one fluid stream to another. Although it is contemplated that the concepts employed in the present invention may be useful in heat exchangers in which at least one of the fluids is a liquid, the primary application of the present invention and the application which is described in the preferred embodiment is an application where both of the fluids are gasses. A common type of heat exchanger is a plate type, non-welded heat exchanger of the type disclosed in U.S. Pat. No. 4,442,886 issued to Dinulescu. The entire disclosure of this U.S. Pat. No. 4,442,886 is incorporated herein by reference.
In general, a plate type, non-welded heat exchanger comprises a plurality or stack of parallel heat exchanger plates. These plates are spaced from one another to define alternate flow channels for two fluids of different temperatures. The plate type heat exchanger as disclosed in U.S. Pat. No. 4,442,886 embodies a generally rectangular configuration referred to as a plate block. The block comprises a stack of generally rectangular plates which are assembled and maintained in parallel relationship relative to one another by a rigid frame assembly. The frame assembly includes corner posts positioned at the corners of the rectangular plates and at right angles to each plate. A pair of connecting end walls join the corner posts and are disposed in parallel relationship relative to the plates. The heat exchanger block configuration of U.S. Pat. No. 4,442,886 defines a pair of opposing first inlet/outlet faces which are parallel to one another and perpendicular to the plates and a pair of opposing second inlet/outlet faces which are parallel to one another, perpendicular to the plates and perpendicular to the pair of opposing first inlet/outlet faces.
The plate blocks of U.S. Pat. No. 4,442,886 can be used separately or can be combined with other blocks to form various configurations of heat exchanger assemblies. The possible configurations can be further increased through the use of additional ductwork and/or a flow manifolds. The possible configurations that can be formed with the blocks of U.S. Pat. No. 4,442,886, however, are limited. For example, in the block of the '886 patent, one of the fluids can enter one of the faces and exit from the same face or from an opposing parallel face, but cannot enter a face and exit from a face which is perpendicular to the entering face. Further, in the block of the '886 patent, the two fluids must enter on different faces. This necessarily limits the configurations which are possible.
Accordingly, there is a need in the art for a heat exchanger unit or block which is capable of overcoming this deficiency, thereby significantly increasing the configurations of heat exchanger assemblies that can be formed.